A communication device according to the second paragraph, comprising a circuit according to the first paragraph, which communication device is enabled to perform the method of controlling a transmission of a transmission data signal according to the third paragraph is known in connection with the international standard ISO/IEC 18092. The known communication device comprises a communication coil that forms transmission means. The communication coil is connected to the circuit. The communication coil is designed to establish an inductive coupling with a corresponding communication coil of a further device during a contact-less communication. The known communication device is designed to transmit according to said standard a transmission data signal to said further device. The further device can be a communication device of identical design or a so-called data carrier that is compliant with the international standard ISO/IEC 14443 or ISO/IEC 15693. The known communication device is also designed to receive according to said standard a reception data signal from said further device. Validity of said transmission data signal and said reception data signal is guaranteed by means of a so called anti-collision protocol. The anti collision protocol provides after its execution on all devices involved in the communication that only one single further device is selected for a contact-less communication with the communication device.
The known communication device shows the problem that the exchange of the transmission data signal and the reception data signal between selected devices can be observed relatively easy by means of e.g. bringing a so-called “spy” device into proximity to one of the devices involved in the contact-less communication and observing or analyzing the sequence or content of the transmission data signal and/or the reception data signal. This fact would basically allow performing a so-called “man in the middle” attack, which attack allows overtaking the role of one of the two legally involved devices for the purpose of e.g. fraudulent activities. In this context in contrast to the legally involved devices the spy device performing the man in the middle attack is a “non-legally” involved device.